A technology of Orthogonal Frequency Division Multiplexing (OFDM) is a kind of multicarrier transmission technology with subcarriers orthogonal to each other, which requires the subcarriers to be orthogonal to each other and is sensitive to the carrier frequency offset. Therefore, the problem of carrier frequency offset becomes one of the principal problems of the current OFDM technology.
At present, to solve the problem of a small frequency offset, there are many methods of a high precision and with simple implementation. However, for the problem of a large frequency offset, the precision for these solutions is relatively low, even though the precision of frequency offset estimation for some methods is improved, the complexity of the implementation are increased.